Edit shopify order with API

[vinodk]

Hello 
I want to edit after placed with Shopify API with graphql OR REST API. Please let me know with example.
I found this but this is not working with order item 

https://shopify.dev/apps/fulfillment/order-management-apps/order-editing#add-a-new-variant

[ShopifyDevSup]

Hi @vinodk  👋

It's a little unclear which part of the order you're looking to edit in your post. If the `orderEditAddVariant` mutation is throwing an error for you, please share an example of each of the below:
 

• the mutation and variables - simplified to the relevant section
• the error returned
• X-Request-ID & timestamp from the last 7 days

With the above details, we would be happy to take a closer look for you. 
 

[touchesport]

im trying to do the same 

I want to upload a PDF to each order from an external couriers API 

either in timeline or metafields